Australian Energy Market Operator

AEMO operates Australia's National Electricity Market (NEM), the interconnected power system in Australia’s eastern and south-eastern seaboard, and the Wholesale Electricity Market (WEM) and power system in Western Australia.

AEMO operates gas retail markets in New South Wales and the Australian Capital Territory, Queensland, South Australia, Victoria, and Western Australia. AEMO also operates wholesale gas markets in south-eastern Australia, those being the Declared Wholesale Gas Market in Victoria (DWGM), the Short Term Trading Market in Adelaide, Brisbane and Sydney (STTM), and the Gas Supply Hub (GSH), whose trading locations are based at Wallumbilla in Queensland, and Moomba in South Australia. AEMO also operates the Natural Gas Services Bulletin Board (GBB), and is system operator of the Victorian Gas Declared Transmission System. AEMO is also responsible for Gas Services Information functions in Western Australia.

Program Information and Fact Sheets

Five-Minute Settlement (5MS) Program

AEMO has established the 5MS Program in order to coordinate the implementation of changes as a result of the Five-Minute Settlement rule change, and the proposed Global Settlement rule change (if the AEMC make such a determination).

Five-Minute Settlement rule

On 28 November 2017, the AEMC made a final determination and rule to alter the settlement period for the wholesale electricity spot market from 30 minutes to five minutes, to align with the dispatch period. The commencement of the change is from 1 July 2021.

The AEMC determined that five-minute settlement would provide a better price signal for investment in fast response technologies, such as batteries, new gas peaking generation, and demand response. The alignment of the operational dispatch and financial settlement periods are expected to lead to more efficient bidding, operational decisions, and investment.

Global Settlement proposed rule

On 16 March 2018, AEMO submitted a rule change to the AEMC proposing that the existing settlement-by-difference methodology which is used in the NEM be replaced with a global settlement methodology. AEMO has identified a range of benefits for this change to be made in parallel with 5MS. The change is expected to involve changes to a number of procedures and systems already impacted by 5MS, and AEMO provided a high-level design outlining the potential impact as part of the rule change request.

Information Sessions

AEMO intends to hold information sessions regularly throughout the program to help inform the broader industry on the changes and the activities that are being undertaken. Slides and notes from the sessions will be published below.